If the ratio of the intensities of two waves producing interference is $49: 16$,then the ratio of the resultant maximum intensity to minimum intensity will be

Two coherent plane light waves of equal amplitude make a small angle $\alpha (\alpha \ll 1)$ with each other. They fall almost normally on a screen. If $\lambda$ is the wavelength of the light waves,the fringe width $\Delta x$ of the interference pattern of the two sets of waves on the screen is:

Diffraction and interference of light suggest

Two monochromatic light beams have intensities in the ratio $1 : 9$. An interference pattern is obtained by these beams. The ratio of the intensities of maximum to minimum is (in $: 1$)

Two coherent sources of intensity ratio $x^2$ interfere. In the interference pattern,which of the following relations is correct?

Two identical light sources $S_1$ and $S_2$ emit light of same wavelength $\lambda$. These light rays will exhibit interference if